The present invention relates to a laser apparatus and, more particularly, to a laser apparatus used together with an endoscope.
Endoscopic laser apparatuses used together with endoscopes have been developed and are commercially available. According to an endoscopic laser apparatus of this type, a YAG laser oscillator is used to generate an operating laser beam. However, since the YAG laser beam is an invisible light ray, the operator cannot confirm the portion of the body cavity on which the beam is radiated. Undesired portions of the body cavity may therefore be radiated with the operating laser beam. In order to prevent this problem, a visible He-Ne laser beam as a marker laser beam is radiated together with the YAG laser beam as the operating laser beam to perform treatment while confirming the radiated portion of the body cavity with the marker laser beam. However, since the He-Ne laser beam is conventionally radiated continuously on the portion, the color (red) of the He-Ne laser beam cannot be discriminated from that of the radiated portion e.g. the walls of a stomach, so that the operator can hardly confirm the marker beam.
Further, in order to determine whether or not the operating laser beam is emitted, the marker laser beam is conventionally split into two beams by a beam splitter. One marker laser beam is used to confirm radiation of the operating laser beam, while the other marker laser beam is guided to the portion to be treated. Therefore, the amount of the other marker laser beam guided to the portion is small. As a result, it is difficult for the operator to confirm the radiated portion with the marker laser beam.